Dynamic headrest

ABSTRACT

A dynamic headrest having a capabilities to move forwardly during an accident or other suitable condition so as to limit injuries to an occupant&#39;s head. The headrest optionally including an actuator configured to move the headrest forwardly in respond to rotary motion of a rotary member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to dynamic headrests of the type that move towards the head of a seat occupant when actuated.

2. Background Art

On Jan. 4, 2001, the National Highway Traffic Safety Administration (NHTSA) published a Notice for Proposed Rulemaking (NPRM) regarding the upgraded requirements and changes to Federal Motor Vehicle Safety Standard (FMVSS) 202. The proposals focused on vehicle head restraints, which became final rule FMVSS 202A that took effect Sep. 1, 2005. One aspect of this rule relates to dynamic headrest. Accordingly, a need exists to provide a dynamic headrest that meets the FMVSS requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is pointed out with particularity in the appended claims. However, other features of the present invention will become more apparent and the present invention will be best understood by referring to the following detailed description in conjunction with the accompany drawings in which:

FIG. 1 illustrates a dynamic headrest seating system in accordance with one non-limiting aspect of the present invention;

FIGS. 2-3 illustrates views of the headrest in accordance with one non-limiting aspect of the present invention;

FIG. 4 a-b illustrate a partial view of an actuator in accordance with one non-limiting aspect of the present invention; and

FIG. 5 illustrates a component view of the actuator in accordance with one non-limiting aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIG. 1 illustrates a dynamic headrest seating system 10 in accordance with one non-limiting aspect of the present invention. The system 10 may be associated with a vehicle (not shown) having a vehicle seat 12 and controller (not shown). The vehicle seat may include a dynamic headrest 14 having capabilities to facilitate moving forwardly in response to signals received from the controller. The forward movement of the headrest may be suitable to satisfy the above-identified FMVSS requirements.

The controller may be configured to instigate or otherwise coordinate actuation of the headrest 14 as a function of any number of vehicle operating conditions associated with a need to impart such movement and/or may the headrest may be directly actuate with signals form system associated with sensing pre/post-crash conditions, i.e., without processing by the controller. The controller may communicate, monitor, or otherwise interface with any number of vehicle elements suitable for use in assessing conditions suitable to actuation of the headrest, such as but not limited to those described in U.S. Pat. No. 5,882,060, the disclosure of which is hereby incorporated in its entirety.

The controller may rely on pre-crash information gleaned from radar detectors, navigation elements, vehicle-to-vehicle warnings, and the like when assessing a need to actuate the headrest. This and other information may be helpful in actuating the headrest prior to or in anticipation of an impending accident or other incident suitable for headrest actuation.

The controller may rely on information received from an accelerometer, air bag deployment sensor, and crash sensors when assessing a need to actuate the headrest. The accelerometer may indicate a rapid acceleration or other change in vehicle operation conditions commonly associated with an accident or other conditions suitable for actuating the headrest 14. The air bag deployment sensor may indicate deployment of the air bag due to a crash or other event. Such crash-based or other vehicle movement based information may be helpful in actuating the headrest after an accident or other incident suitable for headrest deployment.

The present invention contemplates any number of conditions for actuating the headrest and is not intended to be limited to the foregoing. The foregoing describes electronically determined operations and actuating the headrest 14 with signals generated by the controller as a function thereof. The present invention fully contemplates non-electronic or mechanical means and methods for actuating the headrest 14, such as but not limited to other means similarly or not similarly associated with the foregoing pre-crash and post-crash conditions. For example, the headrest 14 may include capabilities to facilitate moving forwardly in response to signals received from pre-crash or post crash conditions, such as but not limited to conditions measured with an accelerometer, manual actuation via occupant acceleration, and/or electromechanical actuation transforming occupant acceleration into electronic actuation.

The system 10 is described with respect to automobiles and other vehicles where it may be desirable to actuation the headrest 14 in response to or in expectation of an accident or other suitable operating condition. The present invention, however, is not intended to be limited to vehicles and actuating the headrest 14 in response to accidents. The present invention contemplates using the dynamic headrest 14 of the present invention in any number of non-automotive or non-vehicular applications.

FIGS. 2-3 illustrates views of the headrest 14 in accordance with one non-limiting aspect of the present invention. The views illustrate an actuator 16 and headrest shell 18 in a pre-actuation position (solid) and actuated position (phantom). The actuator 16 may be configured to impart a rotary motion that results in linear displacement of the shell 18 in a forwardly direction, i.e., toward the occupant's head. One non-limiting aspect of this invention relates to a rotary member 24 24 having a cam 26 and cam follower 28 configured through an interference movement or direct cam follower attachment movement. Another non-limiting aspect may be off-set cams which provide variable displacement versus cam surface rotation.

The actuator 16 may store kinetic energy such that the kinetic energy is released or fired in order to rapidly actuate the headrest 14 in a forwardly direction towards the occupants head. In this manner, the gap between the passenger's head and the headrest 14 is decreased so as to limit neck and head injuries during accidents and other operating conditions. A locking mechanism 34 may be included to prevent the occupant's head from rewardly moving the forwardly deployed headrest. The locking mechanism may include a spring biased locking lever 36 configured to interact with a gear 38 on the rotary member 24 (See FIGS. 4 a-b) such that the headrest 14 is prohibited from moving rearwardly without unlocking the locking mechanism 34 with retraction of a cable 40 connected to the lever.

The actuator 16 may comprise any type of actuator suitable to facilitate moving the headrest forwardly and is not necessarily limited to the illustrated actuator. With respect to the illustrated actuator 16, however, it may correspond with the trigger assembly described in U.S. patent application corresponding with U.S. Ser. No. 11/472,203 that utilizes a smart memory alloy (SMA) trigger 44 to actuate to the rotary member 24, the disclosure of which is hereby incorporated in its entirety.

The actuator 16 may include a plate 46 for supporting a rotary member 24. The plate 24 may be used to connect the rotary member 24 to a cross-bar portion 50 of a headrest support post 52 such that the rotary member 24 is fixed to the post. The shell 18 may include a relief 55, 57 for riding within a laterally extending portion of the support post 52. The shell 18 may be free to displace relative to the laterally extending portion of the support post 52 such that it displaces in a linear direction toward the seat occupant's head with actuation of the rotary member 24, as shown in FIGS. 2-3.

The actuator 16 may include the cam follower 28 connected to a front face of the shell 18, integrally molded thereto, and/or otherwise in communication therewith the facilitate its linear displacement. The cam follower 28 may be moved forwardly with actuation of the rotary member 24. The rotary member 24 may include the cam 26 having a cam portion 56 configured to facilitate linearly moving the shell 18 forwardly about the support post with rotary action of the cam 26. The cam 26 may include a relief with side walls 58 to engage and position the cam follower 28 thereto.

The cam portion 56 may be arcuate in shape such that rotary motion of the cam 26 causes the cam follower 28 to displace linearly at a fixed elevation. The displacement of the cam follower 28 may result in the shell 18 moving forwardly about the laterally extending portion of the support post 52 towards the occupant's head. In this manner, the movement of the headrest 14 towards the passenger is defined relative to the support post 52 used to support the headrest.

The support post 52 may be connected to a receiving unit (not shown) within the seat back. The support post 52 may be vertically or otherwise positioned relative to the seat back and the occupant's head so that actuation of the shell 18 corresponds with desired positioning of the headrest relative to the occupant's head. The support post 52 may be used to position the headrest 14 to any number of locations relative to the occupant's head and with mechanical or non-mechanical operations.

The shell 18 may include grooves 60-62 or channels 64 operable with posts 66-68 and guide 70 of the support plate 46. The posts and guides may extend into the channels of the shell to stabilize movement of the shell relative to the plate. This may be helpful to assure that both ends of the shell 18 move forwardly towards the passenger during actuation. The posts and guides may also be helpful in facilitation assembly of the headrest, and in particular, alignment of the shell relative to the actuator.

FIG. 4 a-b illustrate a partial view of the actuator 16 in accordance with one non-limiting aspect of the present invention. FIG. 4 illustrates the actuator 16 in a loaded or non-actuate state and FIG. 5 illustrates the actuator 16 in an unloaded or actuated state. As shown, the elevation of the cam follower 28 remains substantially fixed during the rotary motion of the cam 26 such that the shell 18 is moved forwardly at a corresponding fixed elevation.

The cam follower 28 may be affixed to an inside face of the shell such that the positioning of the shell relative to the support post 52 is sufficient to secure the cam follower 28 relative to the cam without requiring a permanent mechanical connection between the cam follower and the cam and/or without requiring the side walls 58. This lack of engagement may be helpful in facilitating manufacturing of the headrest as the assembler need only position the shell 18 relative to the rotary member 24, as opposed to having to secure a permanent mechanical connection between the same.

FIG. 5 illustrates a component view of the actuator 16 in accordance with one non-limiting aspect of the present invention. The movement of the actuator 16 may be associated with a power spring 80 configured to impart rotary action to the cam. The power spring may be mounted relative to a reference plate 82 that is fixed to plate 46 and used to define a central axis 84 of the actuator 16, as described in the above-reference patent application. The spring 80 may be biased in a counter-clockwise direction such that it is loaded or otherwise configured to store its kinetic energy for subsequent release.

The actuator may be actuated with the trigger retracting a trigger plate 86 and spring 88 to release an engagement fit between balls 90-94 and the cam 26. The release of the cam 26 allows the power spring 80 to rotate in a clockwise direction, and thereby cause the cam 26 to rotate about the reference plate 82 in order to impart the linear displacement to cam follower 28. The release and actuation of the rotary member 24 may correspond with the release and actuation of the trigger assembly included in U.S. Ser. No. 11/472,203.

From the actuated position (phantom), the rotary member 24 may be reloaded for subsequent actuation by simply pushing rearwardly on the headrest shell 18. The rearward movement restores the power spring 80 to its loaded position. If the illustrated locking mechanism 34 is included, it may need to be unlocked in order to permit the rearward movement. The illustrated locking mechanism 34 is shown for exemplary purposes and without intending to limit the scope and contemplation of the present invention. The locking mechanism 34 may be replaced with any device having suitable capabilities for preventing rearward movement of headrest 14, and which may or may not require unlocking in order to reset the headrest 14.

The ability to reload the rotary member 24, or more particularly the power spring, allows the present invention to provide a resettable dynamic headrest assembly. This may be advantageous in allowing the headrest to be repeatable reloaded over time without having to be replaced. This may be further advantageous over pyrotechnic or other so called ‘limited use’ headrest that require replacement of pyrotechnic devices (air bag) or other more involved processes to reset the headrest.

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.

While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. 

1. A dynamic headrest for use with a vehicle seat having an occupant, the headrest comprising: a moveable shell configured to support a head of the occupant; an actuator configured to move the shell forwardly, the actuator having a rotary motion resulting in linear displacement of the shell; wherein the actuator includes a rotary member configured to rotate about a central axis in order to provide the rotary motion and a cam follower configured to move forwardly away from the central axis against a front face of the shell in order to impart the linear displacement; and wherein the rotary member includes a cam configured to rotate about an end of the cam follower such that the rotary motion of the cam causes the cam to engage the cam follower in such as manner as to impart the linear displacement to the shell.
 2. (canceled)
 3. (canceled)
 4. The headrest of claim 1 wherein the cam follower is fixed to the shell and the rotary member is fixed to a headrest support post.
 5. The headrest of claim 4 wherein the cam follower is not fixed to the rotary member.
 6. The headrest of claim 1 wherein the rotary member includes a spring configured to rotate about the central axis, the spring having a locked and unlocked state, the locked state corresponding with kinetic energy of the spring being stored and the unlocked state corresponding with kinetic energy of the spring being released, the cam configure to rotate with actuation of the spring from the locked to unlocked state.
 7. The headrest of claim 6 wherein the rotary member is configured to reload the spring to the locked state in response to rearward movement of the shell.
 8. The headrest of claim 1 further comprising a support post to support the shell, the shell moving forwardly along a portion of the support post during the linear displacement.
 9. The headrest of claim 1 wherein the actuator includes a guide operable with the shell to guide movement of the shell.
 10. The headrest of claim 1 further comprising a locking mechanism configured to prevent rearward movement of the headrest.
 11. A resettable headrest system comprising: a moveable shell configured to support a head of the occupant; an actuator having a spring rotationally wound about an axis, the actuator configured to release the wound spring such that the spring rotationally unwinds about the axis in order to provide force for automatically moving the shell forwardly, the actuator being resettable with rearward movement of the shell to rewind the spring about the axis for subsequent use in providing force for automatically moving the shell forwardly; and wherein the shell includes guides that slide along headrest support posts when the actuator moves the shell forwardly, the headrest support posts connecting the headrest to a seat back.
 12. The headrest of claim 11 wherein the actuator includes a rotary member configured to rotate about a central axis in order to provide rotary motion and a cam follower configured to move forwardly away from the central axis against a front face of the shell.
 13. The headrest of claim 12 wherein the rotary member includes a cam having a cam portion shaped to rotate about an end of the cam follower such that the rotary motion of the cam causes the cam portion to engage the cam follower in such as manner as to impart linear displacement to the shell.
 14. The headrest of claim 13 wherein the cam follower is fixed to the shell and the rotary member is fixed to a headrest support post.
 15. (canceled)
 16. The headrest of claim 11 further comprising a locking mechanism must be unlocked to permit rearward movement of the headrest.
 17. A dynamic headrest for use with a vehicle seat having a controller configured to anticipate an impending accident and to issue a signal in response thereto, the headrest comprising: a moveable shell configured to support a head of an occupant; an actuator configured to move the shell forwardly upon receipt of the signal wherein the actuator includes a number of gears configured to cooperate with a lever that engages the gears to prevent occupant impact from moving the shell rewardly an element connected to the lever and extending beyond the headrest, the element being retractable to disengage the lever from the teeth.
 18. (canceled)
 19. (canceled)
 20. The headrest of claim 17 wherein the actuator is configured to reload the spring if the lever is lifted and the shell is moved rearwardly.
 21. (canceled)
 22. The headrest of claim 17 wherein the lever successively changes from one gear to the next as the actuator moves the shell forwardly.
 23. The headrest of claim 17 wherein the actuator includes a rotary actuated spring to move the shell forwardly.
 24. The headrest of claim 23 wherein the actuator is configured such that rotary motion of the spring moves the headrest linearly.
 25. The headrest of claim 17 wherein the actuator includes a torsion spring to move the shell.
 26. The headrest of claim 11 wherein the guides slide along a portion of the headrest support posts that is bent at an angle relative to a downwardly extending portion of the headrest support post that connects to the seat back. 